3.1

13 Mean = 30.5167, Median = 31.3, No Mode

14 Mean = 93.1, Median = 87.9, No Mode

15 Mean = 3670, Median = 3830, Mode = 4090

16 Mean = 266, Median = 266, Mode = 260

17

  1. The mean is greater than the median, because the data are skewed right.

  2. The mean and median are approximately equal, because the data are roughly symmetric.

  3. The mean is less than the median, becase the data are skewed left.

3.2

5 Sampe variance = 36, sample standard dev = 6

6 Sample variance = 100, sample standard deviation = 10

7 Population variance = 16, population standard deviation = 4

8 Population variance = 64, population standard deviation = 8

9 Sample variance = 196, sample standard deviation = 14

10 Population variance = 16, population standard deviation = 4

14 Range = 25, sample standard deviation = 7.8

24

  1. 6 seconds

  2. The empirical rule is appropriate for making general statements about the length of eruptions because the data is bell-shaped.

  3. 95% of eruptions last between 92 and 116 seconds.

  4. 95.45%

  5. 16%

  6. 11.36%